Portable projection apparatus

ABSTRACT

A portable projection apparatus has an endless belt running over rollers and a rotatable disk having a band on its outer surface. The endless belt partially embraces the band, and the projection material is accelerated between grooves in the band and the endless belt. The band with the longitudinal grooves can be easily exchanged for other groove cross-sections and the interior surface of the belt is provided with a profiling which runs parallel to the circumferential direction, into which the outer surface of the rollers, guiding the endless belt engage with a corresponding profile.

BACKGROUND OF THE INVENTION

The invention relates to a portable projection apparatus with an endlessbelt running on rollers, and a rotatable disk having a band at its outersurface with the endless belt partially embracing the band and with theprojection material being accelerable between the outer surfaces of theband and the endless belt.

Federal Republic of Germany No. OS 1 073 345 discloses an apparatus forthe production of a beam of granular material in which a band movesaround the partial circumference of a rotating disk. It is adisadvantage of this apparatus that no continuous movement is possiblesince the projection material supply has to be adjusted separately byhand in order for the projection material to be grasped by the band andthe disk. In the case of uneven supply of projection material, the bandslips off because of the lack of a precise forced guidance, and thusthere is no assurance that additional projection material will becarried along and that the apparatus is functional. This apparatus isstationarily arranged.

Such an apparatus was once built and tried by the inventor. It wasconfirmed that it did not work in practical use. The band did not remainon track, ran into the rims, and broke.

It is an object of the invention to provide an apparatus of theinitially-mentioned type in which a secure positive guidance of theendless belt is assured so that the endless belt does not slide off fromthe rollers during the operation of the projection apparatus.Furthermore, a targeted projection of the projection material is to becarried out without the endless belt sliding off laterally. Theretightening of the endless belt can be accomplished in a simplefashion.

The object of the invention is accomplished in that the outer surface ofthe band has longitudinal grooves and in that the interior surface ofthe endless belt has a profiling which runs parallel to thecircumferential direction, into which the outer surface of the rollers,guiding the endless belt, engage with a corresponding profile.

When the band is rotating with the disk, the endless belt, whichpartially embraces the band, is brought along tensionally by the band,with the projection material being located between the grooves of theband and the endless belt. By rotating the band with the disk, thesupplied projection material is grasped, accelerated and then projectedtangentially. The endless belt is forcibly guided with its interiorsurface and the outer surface of the rollers, with the endless belt notbeing able to slide off from the roller laterally. Thus it is assuredthat even in the case of uneven supply of the projection material, theendless belt remains securely in its position. The projection materialis accelerated between the longitudinal grooves of the band and theouter surface of the endless belt. This mode of operation resembles abelt drive, only under different conditions.

Particularly advantageous embodiments of the apparatus in the inventionwill be disclosed in the subordinate claims.

The invention is to be explained further by means of the encloseddrawing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a lateral view of the projection apparatus according to oneembodiment of the invention shown in cross-section;

FIG. 2 is a partial cross-sectional view taken along the line A-B shownin FIG. 1; and

FIG. 3 is a lateral view of the portable projection apparatus accordingto another embodiment of the invention shown in cross-section with aneccentric disk and crank.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 and 2, a disk 2 with a rim or band 3 is operated byan electric motor 1 which is partially shown. The disk 2 has the band 3on its outer surface. This band 3 has conveyor grooves which, with aflange on one side, overlap the surface of the disk and are fastened viaborings with clamping bolts 4 to the disk 2. A projection housing 5provides for the projection and mounting of additional parts. Aprojection material container 6 is rigidly connected to the housing 5 bya strap connection 19. After a control gate has been opened by means ofa control lever 9 which has an open and closed position, the projectionmaterial 7 will slide into the movable hose 10. The hose 10 ispreferably formed as a rubber hose and transports the projectionmaterial 7 to the projection material supply line 11 which is fastenedonto a ring means or a ring target 12.

The ring target 12 is divided transversely and provides for theretightening or tensioning of the endless belt 15 by means of a threadedclamp bolt 16, and carriers the projection material supply line 11, twobelt rollers 14 and 26, the threaded clamp bolt 16 with right- andleft-hand threads, the two thread stops 17 and the swivel arm 18 Ringtarget guides 13 are formed as strap guides to slidably guide the ringtarget 12 on the housing 5. The endless belt 15 runs over the tworollers 14 and 26. The rollers 14 and 26 have a profile 29 on theirouter surface which engages into the profiling 28 on the interiorsurface of the endless belt 15. This profiling, formed as longitudinalgrooves, prevents the sliding off of the endless belt 15 from therollers 14 and 26. In the illustrated embodiment, the profilings 28 and29 run across the entire width of the endless belt 15 and the rollers 14and 26. They engage into one another in a geared fashion. Furthermore,the band 3 has longitudinal grooves 27 which are semicircular incross-section. The projection material is located in these longitudinalgrooves 27 of the band 3 and on the endless belt 15. The produced beam21 hits the object 20 to be projected. A handle 22 is fastened to thehousing 5.

When the disk 2 rotates with the band 3 in the direction of the arrowindicated in FIG. 1, the projection material supplied between the band 3and the endless belt 15 via the projection material supply line 11 isgrasped and brought to the necessary speed so that it hits the object tobe projected 20 as beam 21. With the swivel arm 18, the ring target 12can be adjusted so that the direction of the exiting beam can thereby bechanged. By turning the threaded clamp bolt 16, a change in the tensionof the endless belt 15 can be accomplished via the rollers 14 and 26.

Instead of a swivel arm 18, FIG. 3 shows another embodiment wherein thering target 12 is rotated to relative to the housing 5 by an eccentricdisk 24 with motor. A crank 25 establishes the connection between theeccentric disk 24 and the ring target 12. In this embodiment, theprojection apparatus has a continuously working and rotating ring target12. When this apparatus is operated with the eccentric disk 24, theresult is a larger and extended beam area 23, as compared to the beam21. This additional embodiment has greater advantages since the beamarea length can be adjusted to the workpiece surface. No projectionmaterial is wasted, and the surfaces are hit more intensively andradiated in a shorter time. Manual operation of the swivel arm 18,according to FIG. 1, cannot be accomplished in the same even manner byoperating personnel, resulting in an unclear projection image.

In each of the illustrated embodiments, the endless belt 15 runs withlongitudinal grooves in the two grooved tension rollers 14 and 26, thuspreventing sliding off from the band 3 in the case of an uneven supplyof the projection material. According to FIG. 2, the band 3 guides theendless belt 15 laterally through the rims so that sliding off from theband 3 is prevented here as well. By the pre-tensioning of the endlessbelt 15, this is pressed against the band 3, working tensionally an thusenclosing the projection material 7 in the deep grooves 27 of the band3, effectuating an acceleration through the band 3 and the endless belt15, which resembles a belt drive. The tension of the endless belt 15 andthe adjustment of the divided ring target 12 is effectuated by thethreaded clamp bolt 16 with right- and lefthanded threads.

Apparatus according to the embodiments shown in the drawings has beensuccessful in trial runs.

1. With this apparatus all existing projection means can be used sincethe projection means is not smashed within the apparatus.

2. Higher projection material throughput at smaller motor capacities areachieved since no air has to be conveyed, as in fan blowers.

3. The beam position can be easily and precisely adjusted to the objectto be projected.

4. This apparatus runs without imbalance and is therefore noiseless.

5. The endless belt allows release speeds of up to 80 m/s.

6. This apparatus needs no pre-acceleration, since there is a shocklessand continuously flowing supply at full rotational speed.

7. In stationary apparatus, operating personnel can work under the beamwearing protective gloves, since there is no danger of the bladebreaking and threatening the worker.

I claim:
 1. Portable projection apparatus comprising a housing, a diskmember rotatably mounted on said housing about a central axis, an outerband member mounted on said disk member, said outer band member having aplurality of spaced outer band grooves for receiving projectingmaterial, said band grooves being parallel to one another and extendingendlessly circumferentially around the outer peripheral surface of saidouter band member, a belt means partially in contact with acircumferential area of said outer band member, said belt meanscomprising an endless belt and rollers over which said endless belt isdisposed, said belt means further comprising ring means disposedradially outwardly of said outer band member and rotatably movable onsaid housing, said rollers being mounted on said rings means, andoperable means operably connected to said ring means for rotating anddisplacing said ring means about said central axis such that saidrollers are displaced together with said ring means so that the entirecircumferential area of said endless belt which contacts said drummember is circumferentially displaced about said central axis. 2.Portable projection apparatus according to claim 1 wherein there are twospaced rollers, said endless belt having two runs disposed between saidtwo rollers, one of said runs being in contact with said band member. 3.Portable projection apparatus according to claim 1 wherein said groovesin said band member are semi-circular in cross section.
 4. Portableprojection apparatus according to claim 1 further comprising fasteningmeans for detachably fastening said band member to said disk member. 5.Portable projection apparatus according to claim 1 further comprisingsupply means for supplying projection material between said band memberand said endless belt, said supply means comprising a projectionmaterial supply conduit opening into the converging space between saidband member and said endless belt, said supply conduit being mounted onsaid ring means.
 6. Portable projection apparatus according to claim 5wherein said supply means comprises a supply hopper mounted on saidhousing, and a flexible conduit between said hopper and said supplyconduit.
 7. Portable projection apparatus according to claim 1 whereinsaid housing has a partial circular configuration greater than anopening portion through which the projection material is projected. 8.Portable projection apparatus comprising a housing, a disk memberrotatably mounted in said housing, an outer band member mounted on saiddisk member, said outer band member having a plurality of spaced outerband grooves for receiving projecting material, said band grooves beingparallel to one another and extending endlessly circumferentially aroundthe outer peripheral surface of said outer band member, a belt meanspartially in contact with said outer band member, said belt meanscomprising an endless belt and rollers over which said endless belt isdisposed, said endless belt having an inner surface having a pluralityof spaced belt grooves parallel to each other and extending endlesslyalong the inner circumference of said endless belt, said rollers havinga plurality of spaced projections parallel to each other and extendingendlessly around the outer surface of said rollers, said projectionsengaging said belt grooves such that said endless belt is prevented fromsliding off of said rollers, said belt means further comprising ringmeans rotatably movable on said housing, said rollers being mounted onsaid ring means, said ring means comprising at least two ring segmentswith one of said rollers being mounted on one of said ring segments andanother of said rollers being mounted on another ring segment, andadjustment means operably connected to said two ring segments to movesaid two ring segments relative to one another and thereby adjust therelative positions of said two rollers, thereby adjusting the tension ofsaid endless belt.
 9. Portable projection apparatus according to claim8, wherein said belt grooves extend across the entire width of saidendless belt, said projections in said rollers extending across theentire width of said rollers, said belt grooves receiving and engagingsaid projections in gear-like fashion in cross-section.
 10. Portableprojection apparatus according to claim 8 wherein said two ring segmentsare movable about the axis of said rotatable disk by said adjustmentmeans.
 11. Portable projection apparatus according to claim 8 whereinsaid adjustment means comprises a threaded element threadedly engagingsaid two ring segments.
 12. Portable projection apparatus according toclaim 8 further comprising operable means for rotating said two ringsegments together relative to said housing to thereby vary thecircumferential position at which said endless belt engages said bandmember.
 13. Portable projection apparatus according to claim 12 whereinsaid operable means comprises a swivel arm which is manually movable.14. Portable projection apparatus according to claim 12 wherein saidoperable means comprises a motor driven eccentric disk which operates acrank arm for rotating said two ring segments together relative to saidhousing.
 15. Portable projection apparatus comprising a housing, a diskmember rotatably mounted on said housing about a central axis, an outerband member mounted on said disk member, said outer band member having aplurality of spaced outer band grooves for receiving projectingmaterial, said band grooves being parallel to one another and extendingendlessly circumferentially around the outer peripheral surface of saidouter band member, a belt means partially in contact with acircumferential area of said outer band member, said belt meanscomprising an endless belt and rollers over which said endless belt isdisposed, said endless belt having an inner surface having a pluralityof spaced belt grooves parallel to each other and extending endlesslyalong the inner circumference of said endless belt, said rollers havinga plurality of spaced projections parallel to each other and extendingendlessly around the outer surface of said rollers, said projectionsengaging said belt grooves such that said endless belt is prevented fromsliding off of said rollers, said belt means further comprising ringmeans disposed radially outwardly of said outer band member androtatably movable on said housing, said rollers being mounted on saidring means, said ring means further comprising at least two ringsegments with one of said rollers being mounted on one of said ringsegments and another of said rollers being mounted on another ringsegment, tension adjustment means operably connected to said two ringsegments to move said two ring segments relative to one another andthereby adjust the relative positions of said two rollers to therebyadjust the tension of said endless belt, and adjustment means operablyconnected to said ring means for rotating said ring means about saidcentral axis such that the circumferential area of said band memberwhich is contacted by said endless belt is circumferentially displaced.16. Portable projection apparatus according to claim 15, wherein saidadjustment means comprises an eccentric disc mounted on said housing anda crank arm operably connected between said eccentric disc and ringmeans such that rotation of said eccentric disc operates said crank armto rotate said ring means about said central axis.
 17. Portableprojection apparatus according to claim 16, wherein there are tworollers over which said endless belt passes, said two rollers beingcircumferentially spaced from one another about ninety degrees. 18.Portable projection apparatus according to claim 15, wherein saidtension adjustment means comprises a tension member connected to saidtwo ring segments and operably adjustable to rotate said two ringsegments in the opposite direction about said central axis to therebyvary the circumferential spacing between said two ring segments andthereby adjust the tension of said endless belt.
 19. Portable projectionapparatus according to claim 15, further comprising supply means forsupplying projection material between said band member and said endlessbelt, said supply means comprising a flexible projection material supplyconduit having a discharge end opening into the converging space betweensaid band member and said endless belt, said supply conduit having itsdischarge end mounted on said ring means such that said discharge endmoves with said ring means as said ring means is rotated by saidadjustment means.